For the following exercises, find the linear approximation L(x) to y = f (x) near x = a for the function. 50. [T] f (x) = x + x4, a = 0 51. [T] f (x) =1x , a = 2 52. [T] f (x) = tanx, a = π 4 53. [T] f (x) = sin x, a = π 2 54. [T] f (x) = xsin x, a = 2π 55. [T] f (x) = sin2 x, a = 0